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  • Writer's pictureAsad Lalani


Noise is the second most impactful environmental factor in Europe, after air pollution, according to the World Health Organization (WHO).

In the modern workplace, open-plan office layouts have become increasingly popular due to their collaborative and flexible nature. However, one of the challenges of such environments is maintaining speech privacy and reducing distractions caused by crosstalk among colleagues and patrons. To address these challenges, sound masking systems are often deployed to create a more comfortable and productive workspace. This high-level tech note aims to provide an overview of sound masking solutions tailored for open-plan office environments.

Understanding Speech Privacy

"Speech privacy" refers to the level of acoustic confidentiality within a space, ensuring that conversations remain private and unintelligible to unintended listeners. It is essential to maintain confidentiality during sensitive discussions and prevent distractions caused by overheard conversations. Standards such as ASTM E1130, ASTM E2638, ISO 3382-3, and others provide guidelines for assessing speech privacy and determining appropriate sound masking solutions.

Figure 1 (above) Illustrates a common workspace scenario where a group of individuals engage in conversation near a concentrated work area. Due to their proximity and shared acoustic environment, the sound from the conversation easily permeates into the nearby workstations, leading to annoyance and disruption in work concentration.

The Role of Sound Masking in Open Plan Offices

In open-plan office spaces sound masking systems play a crucial role in enhancing speech privacy and reducing distractions. By introducing a carefully calibrated background sound, sound masking systems raise the ambient noise level, making speech less intelligible and minimizing the distance over which conversations can be overheard. This helps to create a more comfortable and confidential working environment for employees.

Components of a Sound Masking System

A typical sound masking system consists of emitters, power supplies, digital signal processors (DSP), and ancillary components. Emitters are strategically placed throughout the workspace to emit a controlled level of sound, while DSPs adjust and manage sound levels to ensure consistent coverage and effectiveness. The system is often connected using daisy-chain topology using category cables, with standard cables commonly used for deployment.

Deployment Strategies

Sound masking systems are deployed using various strategies to achieve optimal coverage and effectiveness. Some common deployment styles include:

- CEILING-FLUSH (Direct Field) Design

- OPEN STRUCTURE (Diffused Field) Design

- IN-PLENUM (Diffused Field) Design

- UNDERFLOOR (Diffused Field) Design

- IN-DUCT (Focused Field) Design

Each design style offers unique advantages and is selected based on the specific requirements and layout of the open-plan office space.

Figure 2: Illustration of Sound Masking Design Strategies. Each strategy offers distinct advantages. For example, the ceiling flush design can serve multiple purposes, including background music for ambient enhancement and zone-specific paging and voice announcements.

Sound Characteristics and Applications

The sound used for sound masking is specially designed to be adaptive and effective across a broad frequency range, typically between 500 and 8000Hz. This ensures that the masking sound remains unobtrusive while effectively masking speech. Additionally, some sound masking systems offer additional functionalities such as background music, ambient enhancement, and general paging and messaging broadcasts, enhancing the overall user experience in the office environment.

Compliance with Fire Life Safety Regulations

Sound masking systems need to comply with fire life safety regulations to ensure the safety of occupants in the event of an emergency. Many manufacturers offer sound masking systems that are designed to be compliant with fire life safety standards, enabling the system to automatically mute in response to emergency activations from the fire alarm control panel (FACP).


Sound masking solutions are an effective means to create comfortable, confidential, and productive open-plan office environments. By understanding the principles of speech privacy and deploying sound masking systems effectively, organizations can ensure that their employees can work efficiently without distractions, leading to improved overall performance and satisfaction.


This high level technical note has been authored by Asad D. Lalani, Principal Consultant Acoustics & Audio at LC Acoustics to provide readers with an overview of sound masking solutions specifically designed for open-plan office environments. It covers essential concepts, components, deployment strategies, and compliance considerations. For additional information or assistance in designing optimized sound masking solutions for your workspace, please contact our team at [].


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